Device Manager's Hidden "Show Nonpresent Devices" Functionality

Windows' Device Manager hides some devices by default, but it also hides nonpresent devices. Nonpresent devices are ones that are not physically present in the system, but still have configuration information in the Registry.

An Environment Variable can be used to control whether or not Device Manager displays these nonpresent devices, so they can then be deleted (ie: their configuration information can be deleted from the Registry).

For an example scenario of why this might be necessary, please see Microsoft KB269155.

The short of it is this:

• Launch a Command Prompt
• Type set devmgr_show_nonpresent_devices=1
• Type start DEVMGMT.MSC (or just DEVMGMT.MSC)
• Click on the View menu, and then click Show Hidden Devices

You may now select the nonpresent device and uninstall/delete it.